SMT Micro and MC Swivel Shockmount adapters work with the Micro Series Audix Mic's I use them with the 1255's and 1280's. You get much more length on the body of the 1280's than the 1255's so it should not pose any problems. I prefer the MC Swivel over the SMT Micro, as it will allow for better adjustment if necessary.
BTW, mccordo, have the 1290's been discontinued? I have not seen them in quite some time. Also TY for the New Mastersounds on the kickdown.